The Arctic Sea Ice Extent (SIE) measurements I normally post here are important because they reveal how much Arctic Ocean water is exposed to the summer sun. They are also an unambiguous and repeatable measurement from one sensor–it cannot be easily ignored or dismissed.
Arctic Sea Ice Volume, however, is the metric that actually tells us the amount of ice floating in the Arctic Basin. Unlike the SIE, this measurement cannot be derived exactly from direct measurement, but must be modeled from a variety of other measures. Consequently, it is open to interpretation and criticism and I rarely concentrate too much on displaying these results. Its a lot easier for the satellites to tell us how much surface is covered than how much ice is there and denialists are quick to attack this metric as “alarmist”. Still, now that we are just past Arctic Ice Minimum, this is a good time to check this value and compare it with previous Septembers.
Here’s another way of looking at the same data…